Compression brace material with arcuate slits

ABSTRACT

The present invention provides a composite material for use in making orthopedic elastic braces for supporting a body part by compression. The composite material includes center ( 110 ), inner ( 120 ), and outer layers ( 130 ). The center layer having on one side a plurality of grooves ( 100 ) that intersect each other to define a grid pattern functioning as passageways along the width and length of the layer to promote heat and moisture dissipation for the body part being supported. A plurality of cuts ( 150 ) extending through the entire depth of the center layer and distributed across the surface area of the layer, while retaining sufficient elasticity and density to provide adequate compression support. In an embodiment of the invention, the center layer includes a plurality of arcuate slits ( 250 ) defining tab portions ( 255 ) that remain hingedly attached to the center layer.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of prior U.S. patent application Ser. No.09/846,332, filed May 2, 2001, now U.S. Pat. No. 6,508,776 priority fromthe filing date of which is hereby claimed under 35 U.S.C. § 120.

FIELD OF THE INVENTION

This invention generally relates to orthopedic supports and, morespecifically, to a composite material for use in making elasticcompression braces having improved compression support, body heatretention, and breathability during use.

BACKGROUND OF THE INVENTION

Elastic compression braces are available in many forms. Commonly suchbraces are composed of soft, elastic material so that when worn, theyprovide a certain amount of support for an injured joint. These types ofbraces, often purchased without a prescription or the need for skilledprofessional fitting, have been used for a number of years and have beencommonly available as braces for the knee, ankle, thigh, wrist, elbow,chest, or lower back. These resilient, pliable compression braces can beworn for sprains and strains, arthritis, tendonitis, bursitis,inflammation, or to reduce discomfort during post-operative use or totreat post-trauma discomfort.

The elastic compression braces are often made from synthetic rubber(e.g., polychloroprene). This particular material is desirable becauseof its combination of favorable properties useful in elastic compressionbraces. Polychloroprene rubber has good elasticity and a relatively highdensity, thereby providing good compression support and resistance toshear forces.

Polychloroprene rubber is a closed cell material and therefore does notdissipate heat very well during use. Its closed cell characteristics canbe useful in retaining heat during use by reflecting emitted heat backinto the bones and joints of the affected area. This localizedconcentration of heat can aid venous flow, help reduce edema, and makethe soft tissues less susceptible to injury.

Although use of polychloroprene rubber in elastic compression braces canconcentrate heat, the natural tendency of the closed cell material toprevent heat dissipation may cause problems for the user. When worn, thepolychloroprene material braces are stretched to impart a compressionload around the affected body area. This compression fit, combined withthe high density of the material and the lack of air circulation anddissipation through the material, can result in heat discomfort andperspiration and may lead to heat rashes. Prolonged use of such bracescan cause the user to perspire constantly, resulting in discomfort tosuch a degree that the user often stops wearing the brace prematurely.In effect, the material itself dictates the length of time that theorthopedic brace can be worn. It is not uncommon for users to stopwearing such braces after about one to two hours. In an effort toprovide better breathability, certain prior polychloroprene rubberbraces have been manufactured with perforations or holes punched throughthe entire depth of the material. However, these braces may not retainsufficient structural integrity to serve as an effective compressionbrace for the wearer because neoprene material is removed from thesebraces.

Thus, there is a need for an elastic compression brace having sufficientstructural strength and integrity to offer a sufficient level ofcompression support, while also dissipating heat during use to reduce oravoid undue perspiration and heat discomfort, especially duringprolonged use.

SUMMARY OF THE INVENTION

The present invention provides a flexible, resilient composite materialfor use in forming elastic compression braces for surrounding andsupporting a body part by compression. The composite material includes acenter elastic layer, an inner fabric layer, and an outer fabric layer.The elastic center layer is preferably composed of closed cell materialin sheet form, having on one side thereof a plurality of grooves orchannels formed therein to intersect each other to define a gridwork.The pattern of channels provides passageways along the width and lengthof the center layer to enable heat and moisture dissipation for the bodypart being supported.

The center layer also may have a plurality of cuts extending through theentire depth of the layer and distributed across the surface area of thelayer, with the center layer still having sufficient structural strengthand integrity to provide orthopedic compression support.

The composite material may also include an inner layer of flexible,resiliently elastic, porous fabric material bonded to the grooved sideof the center layer. The outer fabric layer may also be composed of aflexible, resiliently elastic, porous material bonded to the non-groovedside of the center layer.

In an embodiment of the invention, the plurality of cuts extendingthrough the center layer are arcuate slits, for example, circular slitsextending between about 180 degrees and 270 degrees, the arcuate slitsdefining an array of tabs that are hingedly attached to the centerlayer, such that stretching the composite material produces gaps in thecenter layer, thereby creating an air flow path between the inner andouter layers.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation view semi-schematically illustrating a kneebrace made from an orthopedic material according to principles of thepresent invention;

FIG. 2 is a semi-schematic perspective view of the knee brace shown inFIG. 1;

FIG. 3 is a cross-sectional view schematically illustrating componentsof a composite orthopedic material of the present invention.

FIG. 4 is a frontal plan view illustrating a section of a puncturedcenter layer of the composite material of the present invention;

FIG. 5 is a back plan view illustrating a section of the puncturedcenter layer shown in FIG. 4;

FIG. 6 is a perspective view illustrating an elbow brace made from thecomposite material of the present invention;

FIG. 7 is a perspective view illustrating a wrist brace made from thecomposite material of the present invention;

FIG. 8 is a side view illustrating an ankle brace made from thecomposite material of the present invention;

FIG. 9 is a view similar to FIG. 4, illustrating another pattern ofchannels formed in the center layer of the composite material;

FIG. 10 is a plan view of a center layer according to another embodimentof the present invention;

FIG. 11 is a plan view of the center layer shown in FIG. 10 with thecenter layer stretched lengthwise, as indicated with the large arrows;

FIG. 12 is a plan view of a center layer according to another embodimentof the present invention;

FIG. 13 is a cross-sectional view of the center layer shown in FIG. 12,taken along line 13—13;

FIG. 14 is a cross-sectional view of the center layer shown in FIG. 13,shown with inner and outer layers attached to the center layer; and

FIG. 15 is a cross-sectional view similar to FIG. 14, showing thecomposite material stretched lengthwise, as indicated with the largearrows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 illustrate a knee brace 20 made from an orthopedicmaterial according to principles of this invention. The orthopedicmaterial is illustrated in FIGS. 3, 4, and 5. The knee brace is a softorthopedic brace made from a flexible, resilient composite 100 shown inflat form in FIGS. 3, 4, and 5. The flat form composite material is cutto shape and sewn or otherwise assembled to form a tubular knee brace20, illustrated in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, a piece of composite material 100 in flatsheet form is folded over on itself. The overlapping long edges on theopposite side of the fold are fastened by a long, upright seam 50. Thematerial in the flat is cut in a shape so that when stitched along seam50, as shown in FIGS. 1 and 2, an angular knee support of generallytubular form is produced having an open top 60 and an open bottom 70.Peripheral stitching 80 at the upper edge and similar peripheralstitching 90 at the bottom edge provide finished edges for the completedknee support.

The components which comprise the composite 100 are best understood byreferring to FIGS. 3, 4, and 5. FIG. 3 shows a cross-sectional viewillustrating the components of the composite 100 of the presentinvention. The composite material includes a flexible and foldablecenter elastic layer 110, an inner fabric layer 130, and an outer fabriclayer 120. The center elastic layer 110 is preferably from a closed cellfoam material in sheet configuration. One preferred elastic closed cellmaterial is polychloroprene rubber, commonly known as neoprene rubber.Preferred neoprene materials are articles of commerce. Another suitablematerial for center layer 110 is styrene butadiene rubber (SBR). Thesematerials are available in a wide density range so it is not difficultto find material of a desired density that provides the desired level ofsupport and provides good orthopedic compression during use. Ideallysuch material for the purposes of the present invention is from 1.5 mmto 8 mm thick. However, other thicknesses may be used. Also, otherelastic closed cell materials may be used to form layer 110.

The center elastic layer 110 has formed therein on one side thereof aplurality of intersecting grooves or channels 140. In non-limitingexample, one embodiment of the present invention shows the pattern ofintersecting channels 140 is formed by placing neoprene sheet materialdown on a metal mesh and then placing a weighted heat source on top ofthe flat sheet material. The pressure and heat cause the mesh to depressinto the sheet material to permanently take the shape of the metal meshon the underside where the grid pattern of the metal mesh is pressinginto the sheet material. In addition or alternatively, the mesh may bepreheated.

In another embodiment of the present invention, a pattern ofintersecting channels 140 is formed on both surfaces of the sheetmaterial. This can be accomplished in one manner by sandwiching thecenter layer 110 between top and bottom metal grids and heat pressingboth grids against center layer 110, causing both grids to depress intothe surfaces of the sheet material. The grid pattern may be identical onboth sides of the center layer 110, or may be of differentconfigurations.

In the embodiment shown in FIGS. 3 and 4, the plurality of intersectingchannels 140 formed in center elastic layer 110 define a generallyrectangular or square-shaped pattern or grid. It is to be appreciatedthat the pattern can be of any other shape (e.g., diamonds (see FIG. 9),triangles, ovals, circles, etc.) as long as the channels 140 intersecteach other so as to provide a continuous or interconnected passagewayacross the sheet material and along the length of the material.

The center elastic layer 110 may be punctured to form a multiplicity ofpunctures or cuts 150 through the layer. Cuts 150 are not shown in FIG.3 for simplicity but are shown in FIGS. 4 and 5. FIG. 4 is a frontalplan view showing a section of punctured center layer 110. FIG. 5 is aback plan view showing a section of the punctured center layer 110 shownin FIG. 4. The multiplicity of cuts 150 are dispersed across the surfaceof center elastic layer 110 and extend through the entire depth of thelayer so that fluids, including perspiration and air, can pass throughthe cuts 150 from one side of the layer to the other, especially whenthe layer is stretched.

In one embodiment of the present invention, cuts 150 are located only inregistry with the channel portions 140. In another embodiment, cuts 150are located not only within the channels 140, but also in theungrooved/channeled portion of elastic layer 110. In a furtherembodiment (See FIG. 9), the cuts 150′ are located only at theintersections of the channels 140′. The multiplicity of cuts 150 may beof uniform pattern and spaced apart uniformly about the center elasticlayer 110. Ideally, the multiplicity of cuts 150 should not be so largeor the cuts must be spaced so close together that the overall structuralintegrity of the neoprene material is reduced beyond the ability of thematerial to provide sufficient orthopedic compression support duringuse.

The multiplicity of cuts 150 may define a cut pattern. FIGS. 4 and 5show that the cut pattern has three “legs” that radiate from a commonpoint. It is to be appreciated, however, that the cut pattern may be anyshape, such as a straight line, a curved line, a cross, or a five-leggedpattern, without departing from the scope of the present invention. Itis to be further appreciated that preferably the puncture does notactually remove any significant material, if any, from center elasticlayer 110 or channels 140; rather, the puncture simply extends throughthe channels. Thus, the puncture does not form a hole or passage throughthe neoprene material unless the material is stretched.

The pattern for the multiplicity of cuts 150 may be formed in centerelastic layer 110 by a number of methods. One such method of forming acut pattern in the neoprene material is by a roller having a cylindricalouter surface with projecting punches in the desired cut pattern so thatrolling the roller over the flat surface of the neoprene materialpunches out cuts in the desired pattern.

Referring back to FIG. 3, composite material 100 also includes a soft,flexible, resilient, porous inner fabric layer 130. Inner layer 130 maybe a knitted flexible and foldable, stretchable cloth fabric materialwhich is porous to air and water because of the pores inherently formedby the knitted fabric. Composite material 100 also includes a flexibleand elastic, porous outer fabric layer 120, which also may be made froma stretchable knitted fabric of the same or different type from layer130. The inner and outer fabric layers 130 and 120, respectively, mayalso be made from other stretchable knitted fabrics including nylon,Dacron or other synthetic fibers.

After the center elastic layer 1110 is altered with a plurality ofintersecting channels 140 on one side thereof and punctured with a cutpattern 150, inner fabric layer 130 is bonded to the grooved face ofcenter layer 110, while outer fabric layer 120 is bonded to thenon-grooved face of center layer 110. Inner fabric layer 130 may beadhered to the center layer 110 using an adhesive technique thatprevents the glue or other adhesive from being placed in channels 140.As such, the adhesive does not close or obstruct channels 140. Outerfabric layer 120 is also glued or otherwise adhered or bonded to centerlayer 110. The adhesive bonds the entire contacting surface areas of thecenter layer 110 and the adjoining inner and outer fabric layers 130 and120, respectively. It is to be noted that the adhesive does not disruptthe porosity of the center layer 110 and the inner or outer layers 130and 120.

Returning to FIGS. 1 and 2, knee brace 20 is intended to be worn withthe grooved/channeled side facing the body of the wearer. This providesthe advantageous result of retaining heat against the body whileallowing knee brace 20 to be breathable. Furthermore, because knee brace20 is made from the composite material, it has sufficient porosity thatinternal heat build-up during use is essentially avoided. Knee brace 20also provides good compression around a body part supported by kneebrace 20 in its stretched condition. The elastic center layer retainssubstantially all of its ability to apply a compression load on the bodyportion being braced because material is not actually removed from theneoprene center layer, as in some conventional braces. Additionally,knee brace 20 is of sufficient density due to the neoprene, SBR, orother selected material to provide the compression necessary to serve asa useful knee brace. The inner and outer layers 130 and 120 also provideadditional compressive strength to knee brace 20.

Knee brace 20 also provides good breathability. When knee brace 20 is inuse, it stretches in a bi-directional manner, thereby creating a pumpingaction to allow air to flow through the channels 140 of knee brace 20.This carries body sweat through channels 140 and out the ends of kneebrace 20. Knee brace 20 also allows fresh, cool air to pass inwardlythrough knee brace 20 to reach the body. Correspondingly, a certainamount of heat is able to pass from inside knee brace 20 to the outsidethrough the plurality of cuts 150, which open up as the brace isstretched during use.

In accordance with a further aspect of the present invention, silicone152, in the form of a gel or beads, may be applied along the inside ofknee brace 20 lengthwise of the brace, perhaps on opposite sides of thebrace. Additionally or alternatively, the silicone beads 154 may beplaced circumferentially around the inside of the brace, perhaps nearthe ends of the brace. The silicone may be applied in a stripe of somewidth, in a narrow line or band, or in other patterns. Moreover, thestripe or line of silicone may be straight or curved. This siliconematerial causes the brace to stay in place on the body due to thefriction between the silicone and the body. The silicone does not,however, cause discomfort or undue rubbing against the body.

In one embodiment, the silicone may be applied to the interior of kneebrace 20 after the brace has been fully constructed. In anotherembodiment, the silicone is applied to the inside of inner fabric layer130 of knee brace 20 and then the inner layer 130 is applied to theinside surface of center layer 110. As those skilled in the art willappreciate, other materials, in addition to silicone, may be employed tocause the brace to stay in place on the body without departing from thescope of the present invention.

FIGS. 6 through 8 illustrate further uses of the composite material 100in compression braces. FIG. 6 shows an elbow brace 160 in whichcomposite material 100 is folded and seamed along its length. The bracemay have an intermediate seam 170 to form a generally L-shaped tubularelastomeric brace. The top and bottom edges of the tubular brace havestitched peripheral seams 180 for edge reinforcement. FIG. 7 illustratesa wrist brace 190 made from the composite material 100, in which thematerial is folded and seamed lengthwise to form a generally straighttubular brace having peripheral stitching 200 at its opposite ends foredge reinforcement. FIG. 8 illustrates an ankle brace 205 made fromcomposite material 100. The ankle brace 205 is formed as a generallyL-shaped tubular brace with peripheral stitching 220 at its oppositeends, peripheral stitching 230 around an edge portion of the brace thatfits around the heel of the user. The brace may include intermediatestitching 240 fastening adjoining intermediate edges of the L-shapedankle support.

These compression braces can be used to provide required levels ofanatomical compression support while improving ventilation to thesupported area to reduce the discomfort caused by perspiration andover-heating. The improved composite material of this invention thusimproves the anatomical support provided by compression braces formedwhen such materials build up, because the user is able to wear the bracefor extended periods rather than having removed the brace prematurelybecause of heat discomfort.

FIG. 9 illustrates an alternative embodiment to the present inventionwherein the composite material 100′ is formed with an elastic centerlayer 110′ having intersecting channels formed therein in a diamondpattern. Also, the cuts 150′ are located at the intersection of thechannels 140′. The channels 140′ and cuts 150′ may be formed in a sameor similar manner as described above with respect to center layer 110.Further, in other respects, the composite material 100′ may be the sameor similar to material 100 described above.

FIG. 10 illustrates a center layer 210 for a third embodiment of acomposite material in accordance with the present invention. In thisembodiment, the center layer 210 is provided with a plurality of arcuateslits 250 that extend entirely through the thickness of the center layer210. The arcuate slits 250 are preferably semi-circular orpartially-circular slits defining approximately 180 degrees to 270degrees of a full circle. The arcuate slits 250 define a plurality oftab portions 255 that remain hingedly attached to the center layer 210,but that can open to allow air flow through the center layer 210. Thecurved geometry of the slits 250 provide a relatively long slit in arelatively short transverse distance on the center layer 210.

The plurality of arcuate slits 250 are arranged in a rectangular, offsetarray, as shown in FIG. 10. The center layer 210 is preferably betweenabout 1.5 and about 8 mm thick, and most preferably about 3 mm thick.The arcuate slits 250 have a diameter D that is preferably between about3 mm and about 10 mm, and most preferably approximately 4 mm. Adjacentoffset lines of slits are spaced apart (in both the vertical and thehorizontal direction as shown in FIG. 10) by an offset denoted OS, whichis preferably between about 3 mm and about 10 mm, and most preferably,about 6 mm. A composite material utilizing the center layer 210 incombination with inner and outer layers 120, 130 (not shown in FIG. 10)discussed above, has been found to produce adequate compressive strengthfor use in orthopedic applications such as compression braces.

The slits 250 are produced in the center layer 210 without removing asignificant amount of material from the center layer 210, whereby whenthe center layer is relaxed, or unstretched, the slits 250 aresubstantially closed.

FIG. 11 shows the center layer 210 of FIG. 10, with the compositematerial stretched elastically in the lengthwise direction (i.e., leftand right in FIG. 11). Crescent-shaped air flow channels 250′ are openedin the stretched panel 210. It will be appreciated that the curvature ofthe arcuate slits 250 produce a relatively large flow area for air andmoisture to pass across the center layer 210. This is due in part to thegeometry of the tab portions 255, which are hingedly connected to thecenter layer 210 along one edge, which partially isolates the tabportions 255 from the stretching stresses in the center layer 210. Thetab portions 255 therefore do not stretch as much as the surroundportion of the material opposite the tab portions 255, producing alarger air flow channel 250′.

When the center layer 210 is relaxed, i.e., when the stretching forcesare removed, the crescent-shaped air flow channels 250′ close,substantially returning to the slits 250 shown in FIG. 10. Inparticular, the tab portions 255 move laterally relative to thesurrounding material opposite the tab portions 255. This opening andclosing motion of the tab portions 255 produce a pumping action withinthe air flow channel 250′ enhancing the flow of air through the centerlayer 210. It will be appreciated that when a soft compressive brace isworn, such as the knee brace shown in FIGS. 1 and 2, movement of thewearer will result in elastic flexure of the brace. Such flexure of abrace made from the composite material described above will thereforeproduce an air pumping action improving air flow across the brace.Moreover, when the wearer is relatively still less heat is generated bythe wearer, and less air flow will be produced by the pumping actionthrough the air channels 255′.

A center layer 310 for a fourth embodiment of the present invention isshown in FIG. 12, wherein a center layer 310 substantially identical tothe center layer 210 shown in FIG. 11 is provided with a plurality ofelongate, shallow grooves or channels 340 that extend laterally acrossthe inner face of the center layer 310. As discussed in detail above,the network of intersecting grooves 340 provide channels that promoteair flow adjacent the wearer's skin, along the inner face of thecomposite material. As seen most clearly in FIG. 13, which shows across-sectional view of the center layer, the slits 350 are preferablypositioned directly adjacent or intersecting the grooves 340 so that airand vapor is directed towards the slits 350, or conversely air enteringfrom the slits is directed towards into the grooves 340.

FIGS. 14 and 15 show a cross section of a composite material 300utilizing the center layer 310. The composite material 300 includes anelastic inner fabric layer 330, preferably a knitted synthetic fiberlayer, that is adhered to the inner surface of the center layer 310. Anelastic outer fabric layer 320 is adhered to the outer surface of thecenter layer 310. The inner and outer layers 330, 320 are adhered to thecenter layer in a manner that will permit at least some of the arcuateslits 350 to open when the composite material is stretched.

The inner and outer layers 330, 320 are porous such that air and vaporcan pass through the inner layer 330, through the arcuate slits 350(when the slits are open) and through the outer layer 320 to vent gassesaway from the wearer, and in the opposite direction to provide coolingair beneath the composite material. FIG. 15 shows the composite material300 stretched laterally, i.e., left to right in FIG. 15. The slits 350are in an open position due to the stretching of the fabric. FIG. 14shows the composite material 300 in an unstretched configuration,wherein the slits 350 are substantially closed. It will be appreciatedby comparing FIG. 15 with FIG. 14 that sequential flexing and unflexing(stretching and unstretching) of the composite material will produce thepumping action discussed above, to facilitate the passage of air throughthe composite material.

Although the slits of the preferred embodiment are semicircular (i.e.,180-270 degrees of a circular arc), any number of other shapes arepossible, and contemplated herein. For example, slits producing elongatetab portions with curved free ends and hingedly attached back ends maybe utilized.

While the preferred embodiment of the invention has been illustrated anddescribed, it will be appreciated that various changes can be madetherein without departing from the spirit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A composite orthopedicsupport material comprising: a center layer made from a stretchableclosed cell material, the center layer having an inner face and an outerface, and wherein the inner face comprises a plurality of intersectingelongate grooves forming a network of channels; a porous, elastic innerpanel attached to the center layer and overlying the inner face of thecenter layer such that the inner panel does not block at least some ofthe elongate grooves; and a porous, elastic outer panel attached to thecenter layer and overlying the outer face of the center layer; whereinthe center layer further comprises a plurality of arcuate slits definingcircular tab portions attached along one side to the center layer, thearcuate slits extending completely through the thickness of the centerlayer and formed without removing significant material from the centerlayer such that the slits are substantially closed when the center layeris unstretched, and the slits produce air flow paths through the centerlayer when the composite material is stretched, and wherein at leastsome of the plurality of intersecting grooves intersect at least some ofthe plurality of arcuate slits.
 2. The composite orthopedic supportmaterial of claim 1, wherein the center layer comprises apolychloroprene elastomer.
 3. The composite orthopedic support materialof claim 2, wherein the porous, elastic outer panel comprises a knittedsheet of material made from synthetic fibers.
 4. The compositeorthopedic support material of claim 1, wherein sequential stretchingand unstretching of the composite material produces an air pumpingaction through the air flow paths by the opening and closing of theslits.
 5. The composite orthopedic support material of claim 4, whereinthe tab portions comprises semicircular segments that are between about3 mm and about 10 mm in diameter.
 6. A compression brace comprising anelastic tubular structure formed from a sheet of the composite materialof claim 1, wherein the tubular structure is formed by sewing oppositelydisposed edges of the composite material sheet together.
 7. Thecompression brace of claim 6, wherein the compression brace is a unitarymember comprising first and second tubular portions that are angularlyconnected.